BMP Paddy Fish Integrated Farming

Introduction:

Assam is one of the North Eastern states of India wherein paddy cultivation is the main occupation in rural areas and rice is the staple food for the people and it forms an essential part in their lives and culture. It has been observed that along with paddy farming, fish cultivation in Assam has evolved over a period of time due to increasing demand for fish for local consumption. Among the most popular integrated farming practices, paddy-cum-fish integrated farming is a highly beneficial practice for rural farmers. The paddy-cum-fish culture is an innovative farming system in which paddy is the main crop and fish is taken as an additional crop to earn extra income by using the same farming area. The majority of farms in Assam are affected by floods during the monsoon season as most of the lands are in low lying areas highly vulnerable for climate risks. Therefore, paddy-cum-fish farming as a climate resilient farming practice gives an opportunity to increase their productivity and provide a reliable source of income and employment for the rural farmers apart from nutritional security.

Traditionally, paddy-cum-fish culture in Assam is practiced in flooded river basins, unmanageable vast waterlogged areas and perennial waterlogged wet rice lands, where fishes enter into the fields during monsoon and grow along with paddy. Fishing activities start after the recession of water during November-December and the fish farmers use various fishing gears like cast nets, gill nets, lift nets and also various traditional indigenous traps either operated in the rice-free spots of the field or fixed at appropriate water entry and exit points in the fields. The paddy-fish farming system contributes to 5.43 % of total fish production in the state and around 2.3 million ha of seasonally flooded paddy cultivated lands of Assam have the potential for fish production along with paddy farming.

In Assam, fishes are introduced intentionally and are also found naturally in the paddy fields which enter from the adjacent water bodies. Paddy species which grow in low lying areas or flood prone areas are broadly termed as “Baudhan” in Assam. Unfortunately, productivity and viability of conventional paddy-cum-fish farming system is very low in the state due to the lack of proper technological interventions in paddy-cum-fish farming practices followed by the farmers. Better Management Practices (BMPs) integrating both the paddy and fish farming practices is essential to increase the productivity and viability of both paddy and fish under such integrated farming systems.In paddy –fish systems, paddy and fish forms a mutualistic symbiosis as:

• Fish excreta provides nutrients for paddy
• Fish control insect pests in paddy field by feeding on herbivore insect eggs and larvae. They also feed on planktons and small aquatic macrophytes
• Paddy provides fish with shelter and fish also get natural food from paddy plot (insect eggs, larvae, and plants)

Management Practices

Paddy-fish farming system is an integrated farming system, where fish is grown concurrently or alternately with paddy. Flooding is a major problem in some of the districts/low lying areas of Assam. In response, paddy-fish farming systems (rice + fish) is farmed concurrently during Boro/Dry season and continuing rearing fish in inundated paddy field during Sali/Rainy season has evolved as a climate resilient practice. Paddy-fish farming plots are surrounded by strong dykes. In Boro season, paddy is grown in 2/3rd area of the plot while fishes are stocked in deeper section of the plot (1/3rd of the area). Upon harvesting Boro rice, whole plot resembles like a pond as water level rises after the rainy season. Farmers continue growing fish (that was stocked in the Boro season) in these systems as planting Sali rice is not feasible due to increased water depth. Paddy-fish farming is more common in central (Morigaon and Nagaon) and lower (Nalbari) Assam in Boro and Early Ahu season where paddy fields get inundated for considerable period during Sali/Rainy months.

BMP for Paddy-cum-Fish farming:

Paddy varieties:

Paddy varieties:

Paddy varieties:

• Seed should be clean (contains no stones, soil particles, weed seeds), genetically pure (contains grains of only one variety) and healthy (full big grains, same colour, no cracks, no obvious disease or pest attack).
• Procure quality seeds of recommended paddy varieties through ATMA/KVK, Department of Agriculture/AAU/IRRI approved seed suppliers

Seed selection:

• Seeds are immersed in clean water and stirred well.
• Seeds those sink are selected, and those that float are rejected.
• Seeds those sink are selected, and those that float are rejected.

Seed treatment:

• Once the selection process is done, the seeds should be soaked directly in one of the following fungicidal suspensions for 12 hours.
• One liter of fungicidal solution is required to treat one kg of seed.
• Treated seeds should be kept in incubation for 24-36 hours before sowing in nursery beds

OR

• Treat the seed with Trichoderma harzianum @ 10 g /kg seed overnight or 6 hrs before sowing.
• Dry the seed in shade for 30 minutes after seed treatment.

Nursery raising:

Time of sowing: January-February season is the most appropriate time for raising nursery for targeting the transplanting after 25-30 days when they are at 5-6 leaf stage.

Seed rate: 40-45 kg per hectare

Nursery-bed size:

• For one hectare of main field, the nursery seedbed size should be between 750 and 1000 m2 and not more than 1/10th of the main field size.
• Land is thoroughly puddled and seed beds of 10m length and 1.25m breadth, 15 cm height are prepared with 50 cm gap in between the beds.
• The length of the bed may vary according to convenience and availability of space.

Irrigation: Irrigate as per the requirement to maintain water saturated condition of the seed-bed. Maintain 2-3 cm standing water for 2-3 days prior to uprooting.

Nursery fertilizer:

Plant protection: Adopt plant protection measures in the standing nursery as per standard package of practices

Seedling priming against insects: As protective measure against stem borer, gall midge and hoppers, the uprooted seedlings are first washed and then root portion is dipped into 0.2% solution of Chlorpyriphos (2 ml/lit of water) along with 1% urea (10g/lit of water) for 3 hours. Alternatively, in standing nursery 5-7 days before uprooting, apply or spray Chlorpyriphos 20 EC @ 0.2%.

Trench/pond preparation:

• Create a pond or ditch for 30% to 40% of the main field area with a depth of 3-4 feet at the lowest side of the paddy plot, and raise the dyke to a minimum of 2 feet above the local flood height at peak rainy season
• Renovate the existing canals, pond and trenches to retain water for the fishes during the summer months
• Install inlet and outlet pipes for maintenance of water level during the culture period.
• The inlets and outlets should be guarded by bamboo split or wire/plastic mesh (Bana) to prevent weed fish and aquatic predators from entering into paddy fields and to prevent escape of the stocked fishes.
• Liming should be done in the pond/trench area as well as in the canals of paddy field with Quicklime at a recommended rate of 80 kg/ha

Main Paddy field Preparation:

For preparation of the main plot, the following points should be kept in mind:

• Field should be prepared thoroughly by ploughing 4 to 5 times, followed by harrowing and laddering. Ploughing should be started at least 21 days before transplanting so that weeds are dried up/decomposed. Alternatively, one pass of mouldboard plough followed by one or two passes of modified helical blade puddler to be done for obtaining good quality puddled soil.
• The ploughing intervals should be spaced such that the weeds germinating after the first round of ploughing are ploughed up in the next round.
• If available, apply compost or well decomposed farm yard manure uniformly prior to field preparation and mix it well with soil.
• Repair the bunds to prevent water leakage from the field during the cropping season.
• Field should be puddled and levelled well, better maintaining a thin and uniform layer of water
• The basal fertilizer dose is applied to the field as per recommendation in the Table below:

Transplanting:

Seedling age: Always use 25 to 30 days old (5-6 leaf stage) seedlings for transplanting for better yield

Spacing: Transplant at distance of 20 x15 cm (8x6 inches)

Seedling density: 2-3 seedlings per hill

Depth of seedling: 4-5 cm

Fish stocking:

• After 10-15 days of paddy transplantation, stocking of fishes can be done.
• Procure quality fish seeds from department hatcheries, multiplication centres or Registered Private hatcheries (where available improved Jayanti Rohu, Amur carp seeds)
• Procure fish seeds of 10 cm size for stocking. If fingerlings available in local hatcheries are small (< 5 cm), procure in advance and nurse them in nursery pond until they grow to 10 cm;
• Treat the fish seed with KMnO4 @1-3 ppm or NaCl @4% before stocking
• Maintain stocking density (10000 nos/ha) as recommended
• Feed the fingerlings with high quality farm made feed by mixing Mustard oilcake and Rice polish in the ratio of 1:1 applied twice daily at the rate 2-3% of fish biomass.

Fertilizer management for paddy:

• For transplanted rice, fertilizer recommendation per hectare is as per Assam Agricultural University recommendations for paddy-fish farming.
• The nitrogen dose is split into 3 equal applications - about 1/3 as basal, 1/3 at tillering and 1/3 at panicle initiation.
• The detailed schedule and method of applying all nutrients is given in the table below:

Water quality management for fish culture:

Monitor the pond regularly for Dissolved Oxygen and pH Low Dissolved Oxygen stress symptoms:

• Fish come to surface and gasping for air
• Shows lethargic behavior
• Stop eating feed

Low Dissolved Oxygen stress is likely:

• If the pond is dark green with Secchi disc visibility of <15 cm (DO stress occurs either very early in the morning or when the day is cloudy)
• If pond water is dark/black colored with foul smell (e.g., H₂S)
• Low Dissolved Oxygen stress occurs either early in the morning or when the day is cloudy

Check pH after heavy rainfall and apply quick lime if pH is < 6.5 at the rate of 200 kg/ha

Weeding: Keep the field weed-free especially in the early stage of crop as weeds do most damage in early crop stage. But later control is also important to prevent seed setting by weeds.

Hand weeding: 1st weeding 3 weeks after transplanting and 2nd weeding 6 weeks after transplanting

Feeding the fishes:

Follow feeding options, depending on the feed availability and costs:

• Floating pellets
• Sinking pellets
• Farm-made feed
• Combination of commercial formulated feed and farm-made feed
• Adjust feeding rate as recommended

Plant protection measures:

• Follow plant protection measures as per the recommendations. But no pesticides/herbicides to be applied in in paddy –fish farming system as it will result in mortality of stocked fishes.

Regular sampling of fishes:

Do sampling of fishes every month to assess the growth and health of the cultured fishes:

• Monitor the length and weight of different species of fishes stocked.
• Use the information for adjusting the feeding rates
• Check for the presence of external parasites on the body surface, fins, gills etc. and also for the presence of lesions or wounds.
• Adjust feeding rate based on total fish biomass in the system: (fish biomass (kg) = average size of fish (g) x to number of fish stocked (n)/1000.

Disease management of fishes:

Unlike pond culture, incidence of fish disease is low in paddy –fish system. There are a number of preventive measures farmers can follow to reduce the risk of diseases and parasitic infection:

• Stock pond with healthy, disease-free seed.
• Disinfect all tools used in fish culture operations.
• Avoid overcrowding.
• Follow proper feeding, fertilization and water quality management practices.
• Conduct routine screening for any sign of disease/stress.
• Record all clinical signs; take pictures of clinical signs, and record of number of dead fish.
• Remove all moribund and dead fish, and bury them far away from the pond.
• Bring any unusual mortality to the attention of responsible authorities and assist them to collect sick and moribund samples for laboratory testing.
• Follow the suggestion of the responsible authority for disease management.

Harvest and post-harvest of paddy:

• Harvest when 80-85% of the grains attain physiological maturity i.e. visually straw coloured
• Minimize the time during which the harvested plants remain in the field and avoid field drying. Make sure that the panicles stay dry.
• Thresh and dry within two days after harvesting. Where available, adopt mechanised drying using solar bubble dryer. In the absence of mechanised drying, alternatively follow Sun drying on a mat or plastic sheet, keeping the thickness of the grain layer 3 to 5 cm.
• Clean the grain thoroughly by winnowing. Store the rice in cool, dry and clean storage bins.

Fish harvesting:

Follow harvesting strategy based on culture system, growth of fishes and market conditions–

• Generally single stocking multiple harvesting is recommended
• Partial harvest after 5 months to thin the stock by harvesting the bigger fishes
• Harvest fishes when they grow to marketable size
• Condition fishes overnight in holding tanks with sufficient aeration and water circulation before sending live to market to reduce mortality

Marketing of fish:

• Transport fish to market either early in the morning or late in the afternoon
• Preferably send fishes live to the market to get better prices
• For distant markets, pack fish with adequate ice and transport in insulated trucks

Environmental care:

Make sure that fish farming activities are not causing damage to surrounding aquatic and terrestrial environment.

Particulars	Paddy-fish farming (per ha during Boro/early Ahu season) with BMPs	Normal farmer practice without BMPs

Record keeping:

• Maintain records of all farm activities, stocking details, inputs, sampling details, harvest details, sale and also consumption.
• Use record books provided under the project for keeping records.
• Ensure the records are updated periodically with the support of Project staff or Department officials during their visit.

Paddy-fish farming calendar:

Follow the farming calendar presented below:

Partial Harvesting